Recently, since stereoscopic (3D) displays become more popular with the development of display technique, various manufacturers have invested heavily in the stereoscopic display field and they are competing fiercely with each other. Currently, techniques of stereoscopic display with glasses are typically used among the stereoscopic display techniques, and the main techniques of stereoscopic display with glasses can be divided into shutter stereoscopic display technique and polarization stereoscopic display technique. For the shutter stereoscopic display technique, stereoscopic display is realized by increasing the refresh frequency of an image. Images with full high definition can be provided by the shutter stereoscopic display technique because there is no loss of image resolution. Moreover, no additional component needs to be added to the liquid crystal panel because only the refresh frequency needs to be increased; therefore the cost thereof is lower. However, the shutter stereoscopic display technique involves the following disadvantages: low brightness, heavy and expensive glasses which need to be charged and have flicker and crosstalk between images. For the polarization stereoscopic display technique, the original images are decomposed into two groups of images, i.e., the polarized light in the perpendicular direction and the polarized light in the horizontal direction by use of the principle of vibration direction of light. Since the left lens and right lens of the 3D glasses are made of polarized lenses with different polarization directions separately, two groups of images are individually received by the left eye and right eye of a human through the 3D glasses, and then synthesized into a stereoscopic image by the human brain. Currently, the circular polarization is conventionally used in the polarization stereoscopic display technique to realize stereoscopic display. Compared with the shutter stereoscopic display technique, the polarization stereoscopic display technique has the following advantages: the 3D glasses are simple in structure, low-cost, convenience for wearing, and does not need an electrical source; and the image brightness is higher than that of the shutter stereoscopic display technique, and the wearer does not feel dizzy due to flicker because there is no shutter disposed therein.
Because of the above advantages, the polarization stereoscopic display technique becomes currently the main technique in the stereoscopic display technique field. The polarization stereoscopic display technique can be realized by a stereoscopic display apparatus. FIG. 1 is a schematic view showing the structure of one stereoscopic display apparatus in the prior art. As shown in FIG. 1, the stereoscopic display apparatus may comprise: a liquid crystal display panel 1, polarizing films 2 and a phase retardation layer 3, wherein the polarizing films 2 are formed on the liquid crystal display panel 1 and the phase retardation layer 3 is formed on the polarizing film 2 that is disposed on the light-emitting side of the liquid crystal display panel. The phase retardation layer 3 can comprise: an alignment layer and a thermotropic liquid crystal layer disposed on the alignment layer, such as a liquid crystal layer formed by the reactive mesogen (hereinafter referred as “RM”). During the production of a stereoscopic display apparatus, the phase retardation layer 3 can be directly formed on the light-emitting side of the polarizing film 2, and during the formation of the phase retardation layer 3, it is necessary to perform an exposure process with ultraviolet rays (hereinafter referred as “UV”) to the material for forming the phase retardation layer 3. During the UV exposure process, the alignment of the phase retardation layer 3 with the liquid crystal display panel 1 is realized by an exposure device, and has improved alignment accuracy compared with the alignment obtained by laminating. However, in the prior art, the phase retardation layer 3 formed on the light-emitting side of the polarizing film 2 is disposed at the outermost and the material for forming the phase retardation layer 3 does not have humidity resistance and scratch resistance, therefore the phase retardation layer 3 would lose the properties thereof gradually if no protection is provided, thereby causing the deterioration or failure of the stereoscopic display effect of the stereoscopic display apparatus.
A protection film 4 is generally formed on the phase retardation layer 3 to solve the above-mentioned problem, and the protection film 4 is usually a polyethylene terephthalate (PET) film or a cellulose triacetate (TAC) film. Since the protection film 4 is a preformed film, it is still necessary to laminate the preformed protection film 4 onto the phase retardation layer 3 by laminating equipment, and thereby both the equipment investment and the production cost are increased.